Continued smoking after cancer has been diagnosed is associated with a poor treatment outcome and a low overall survival rate. However, on learning about their cancer diagnosis, many patients who smoke continue to use tobacco. Even among patients who quit, many fail to maintain long-term abstinence. Therefore, it is important for researchers to study the mechanisms that underlie smoking motivation and abstinence failure in cancer patients. The objective of this proposed project is to study the relationships between pain, smoking motivation, and smoking cessation among patients with head and neck cancer. The specific aims of this project are to 1) examine the relationship between pain and smoking-related variables (e.g., negative affect, urge, self- efficacy) in patients with head and neck cancer who smoke, 2) identify nicotine's antinociceptive effect on pain in patients with head and neck cancer who smoke, and 3) determine the effect of smoking abstinence on pain in patients with head and neck cancer. The proposed project is a naturalistic study that uses ecological momentary assessment (EMA) to assess pain, cigarette use, and other smoking-related variables in head and neck cancer patients who smoke during a 4-week monitoring period. EMA refers to a method that uses a palmtop personal computer (PPC) to measure human behaviors at the moment of their occurrence in natural environments. Participants will include 40 head and neck cancer patients who smoke and are referred to the Tobacco Treatment Program for smoking cessation treatment. All participants will attend 1 baseline and 2 study visits. During the baseline visit, prospective participants will be screened for inclusion and exclusion criteria. Eligible participants will complete a battery of questionnaires that is designed to measure predispositions variables of smoking that include affective vulnerability, nicotine dependence, enduring coping style, self-efficacy style, enduring cancer-related symptoms, and perceived stress level. They will be given a PPC and trained in its use. Participants will be instructed to start using the PPC for EMA monitoring 2 weeks before their anticancer treatment begins and to continue until 2 weeks after the beginning of their anticancer treatment. During this 4-week EMA monitoring period, participants will be asked to complete 4 types of assessments (daily diary, temptation, smoking, and lapse) that include both core (e.g., pain, affect, urge to smoke, abstinence self-efficacy) and unique (e.g., daily intake of pain medications) items. Participants will return the PPC during the first study visit, which will be scheduled approximately 2 weeks after the beginning of their anticancer treatment. The second and final study visit will take place at approximately 3 months after the beginning of the participants'anticancer treatment. At both visits, participants will complete the same battery of questionnaire as they will during the baseline visit. Furthermore, study personnel will assess participants'smoking abstinence and administer breath and saliva cotinine tests to confirm self-reported abstinence.